318 Engine Build - A Parts Book 400HP 318

What else can you say? TTI...        read full caption What else can you say? TTI step headers are hard to beat.

We used MSD ignition components...        read full caption We used MSD ignition components exclusively, including the distributor, wires, and ignition box.

We selected a 750 Mighty Demon...        read full caption We selected a 750 Mighty Demon for its power potential, and deliver it did, topping out exactly at 400 hp at 6,150 rpm with some tweaking. We were more than happy with our 318 combo--this little engine screamed!

Putting It Up
To see if this 318 would meet our lofty goals, we brought our fresh mill to Westech's engine dyno facility to post some numbers. The assembled long-block received an MSD distributor and wires, a set of tti 15/8--13/4-inch step headers, and a 750 Mighty Demon carb--all top components we were confident using. The 318 cracked to life, and we ran the engine through the normal break-in cycle with the distributor set to provide 34 degrees of total timing. Idling down, the 318 sounded sweet commanding 10.5-inches of vacuum and exhibiting a mild loop. With the first real power pull, we recorded 383 hp at 6,200 rpm, stout output but a little shy of our goal of 400 hp. One thing was clear, the little 318 did love to rev. A timing loop followed, as we sought to zero in on the ideal timing and found the best overall curve with total advance set to 36 degrees. Power nudged up only slightly, now reading 385 at the same 6,200 rpm. A jetting loop followed, but there wasn't anything to be found after making several jet changes.

We noted the fresh engine was producing a maximum of 95 psi of oil pressure hot with the 20w-50 oil we used for break-in. It seemed as though a lower viscosity oil would be worth a couple of numbers, and better still, a nice synthetic may add even more output. We drained the sump for a fill of 10w-30 Royal Purple and found more than we expected, with power now up to 394 at 6,100 rpm. We were tantalizingly close to the 400 mark, and still had a trick or two to try. A Wilson 1-inch tapered spacer was sandwiched between the intake and carb, and we hit pay dirt--400 hp on the nose at 6,150 rpm!

Dyno Results
Superflow 901 Dyno
Tested At Westech